Modern printing systems, such as laser printers, print images on substrates using printing fluid (e.g., ink, toner, or the like). The printing fluid may be dispensed from a disposable or refillable cartridge which contains an amount of printing fluid sufficient to print a finite number of pages. When the printing fluid is used up, the printing system may not be able to print further pages until the cartridge is replaced or refilled. Thus, users of the printing system may find it helpful to know how many more pages the system is capable of printing, so that they can plan their print jobs and/or obtain replacement cartridges accordingly.